﻿    <p>
      Boolean operators that apply to the first and second Boolean
      operands.
    </p>
    <blockquote class="extDef">
      NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
      This type defines the three Boolean operators used in the
      definition of CSG solids.
    </blockquote>
    <blockquote class="note">
      NOTE&nbsp; Entity adapted from
      <strong>boolean_operator</strong> defined in ISO 10303-42.
    </blockquote>
    <blockquote class="history">
      HISTORY&nbsp; New entity in IFC1.5.1.
    </blockquote>